Hi,
There is no need to add any category or product to your custom field, it will apply automatically to all the products by default.
The message "You need to publish at least one another field of the same table first" displays for the option "Display limited to" because you can only use that option once you have at least another field configured since when you limit the display of the field, you can only do it based on the selected value of another field. If you see that message, it means that you didn't configure another custom field for the same table.
If you have set the field to yes everywhere, it will display. I suppose that you're creating a custom field of the table "product", which is for adding data to your products in the backend, while what you want is actually to create a custom field of the table "item", which is displayed on the product page in the frontend for the user to use it.
That's the first thing we explain in the documentation regarding the custom fields:
www.hikashop.com/support/support/documen...shop-field-form.html
We welcome your comments on the user interface as we try to improve it, release after release, but there is no need to write in uppercase or insult us or the software.